For test, rehabilitation and exercise machines where rotary motion of a person's musculature is involved, it is important to be able to limit the range of rotary motion so that injury does not result from over rotation. Also, for the effective rehabilitation of certain musculature over a certain specified range of rotary motion, for example trunk musculature involved in trunk extension and flexion, it is important to limit the range of rotary motion so that the rehabilitation can be focussed on that part of the range of rotary motion which needs the rehabilitation.
In a test, rehabilitation and exercise machine which permits a person to engage in trunk extension and trunk flexion movement, it is often necessary to limit how far the person extends the trunk or flexes the trunk. If a person has only a limited ability to extend his or her trunk (i.e., bend backward at the waist), or flex his or her trunk (i.e., bend forward at the waist), trunk extension or flexion beyond a certain point in the rotary motion could very well cause serious injury to the back. The value of a trunk extension/flexion test, rehabilitation and exercise machine is severely diminished if no provision is made for limiting the range of rotary motion.
Also, the means for limiting the range of rotary motion must be adjustable to any position along the range of motion, so that the trunk extension/flexion machine can be used with a wide variety of persons with different range of rotary motion limitations.
Further, the adjustment of where the range of rotary motion is to be limited must be quick and easy to accomplish, so that persons with different range of rotary motion limitations will not have to wait for treatment on the machine due to the delay caused by the adjustment.
Exemplary range of motion limiting apparatuses for limiting rotary motion on exercise machines are shown in U.S. Pat. Nos. 2,855,199 to Noland et al and 4,492,375 to Connelly. General range of motion limiting apparatuses for limiting rotary motion are shown in U.S. Pat. Nos. 3,505,884 to Ford et al and 1,004,388 to Dickert.